Cradle assembly for stranding machine



Feb. 28, 1961 2,972,854

c. o. 'BRUESTLE CRADLE ASSEMBLY FR STRANDING MACHINE TiTl.

Filed April 2, 1958 2 Sheets-Sheet 1 INVENT OR. 634m Q fizz/55mg QMKQMLM 1961 c. o. BRUES'TLE 2,972,

CRADLE ASSEMBLY FOR STRANDING MACHINE Filed April 2, 1958 2 Sheets-Sheet 2 ITrMA/B J United States PatentO 2,972,854 CRADLE ASSEMBLY FOR STRAN DING MACHINE Carl OLBruestle, Metuchen, NJ., assignor to s n'm Machine Company, Perth Amboy, N.J., a corporation of NewJersey I Filed A r. z,19ss,- ser. 0. 725,3 24 i 2 Claims. or. 57-65) Thecradle assembly of this invention forms part of a cable stranding machine. 7 a g a These machines are well known in the artin various forms and are provided for the purpose of building up relatively large twisted cables composed of a plurality of smaller strands which are fed concurrently to the nosepiece of the machine. The twisting of the strands into the cable proper is effected by rotating the main shaft of the machine on which are in turn rotatably mounted a plurality of cradles constructed to support supply spools for the strands. The cradles are rotatably mounted on axeswhich are radially offset from the axis of the main shaft of the machine, so that the cradles rotate bodily about that axis as they in turn rotate each on its own,axis,"which is parallel to'the axisof the main shaft.

' Each cradle is constructed so as to in'turn' rotatably support the'spool strands thereon, the axis of which rotation for each cradle is at right angles toits axis of rotation. The cradle assemblies and loaded spool strands are relatively heavy, with the result that their planetary motion about the axis of the main shaft of the machine results in the. development of very large operational stresses which in turn require not only a heavy construction for the mainparts of the machine but also for the cradles.

Patented Feb. 28, 1961 2 without stressing the other bearing or the side frame members of thecradle.

Further in accordance with this invention, provision is made, after the spool is mounted in the cradle, for

locking the bearing assemblies therefor in the cradle so that in cooperation with thetie bar cross connection of the side frame members is effected for transference of As-is well understood in the art the cradle frames,

due to the reversal offorces encountered as they revolve about the main shaft and on their own axes of rotation, alternately subject the side members of the cradles to rapidly and successively occurring maximum and minimum stresses. Thus since each side member of the cradle is alternately subjected to a maximum stress, each cradle has to be of sufficiently heavy construction to Withstand such stresses.

A prime purpose of this invention is to provide a novel arrangement in which the side frame members of each cradle arecross-connected or tied together during operation of the machine so that the stresses applied to one side member will be transmitted to and divided with the other side member. This shifting of stresses occurs alternately as the cradle revolves not only about the main shaft of the machine, but on its own axis.

Further, in accordance with this invention the crossconnection of the side frame members of the cradle is eflfected by means of a tie bar which lies axially of the strand spool, rotatably mounted on the cradle, and passes through the core of the spool so that it may not escape from the cradle during the operation of the machine unless the tie bar breaks or comes loose.

Further in accordance with this invention it is proposed to provide a construction in which the bearings which rotatably support the strand spool are capable of respective endwise movement under the influence of a tie bar so that when the spool is mounted in the pintle assemblies of which the bearings are a part, one of these the stresses back and forth in the operation of the machine.

Other and more detailed objects of the invention will be apparent'from'the following description of the embodiment thereof illustrated in the accompanying drawings including the advantage that by this construction the cradles maybe of lighter construction than otherwise possible. 1 i

In the accompanying drawings,

Figure 1 is an elevational view of sufficient of a planetary cable stranding machine to illustrate this invention showing one of the cradles in the plane with the strand spool mounted therein;

Figure 2 is a side elevational view of the cradle; and

Figure 3 is a cross-sectional View taken on the line 33 of Fig. 2. i

I As diagrammatically illustrated, a planetary cable stranding machine includes the main rotor shaft 10 which is rbtatably mounted in bearings, not shown, and which provided. at the cradle positions with radial arms or spiders 12 and '14. Rotatably mounted in suitable bearings 22 and 24 at the outer ends of these arms, is the cradle which is generally, indicated by the reference numeral 16. This cradle is provided at its ends with subshafts which are jourualed in the bearings 22 and24 so that the cradle is rotatably mounted on its longitudinal axis which is parallel to the axis of rotation of the main shaft 10. The cradle 16 is of generally rectangular-open form, including the side frame members 18 and 20 which .are formed to provide a pair of aligned bearing housings or strand spool supporting fixture 34 attached to the other end. This fixture is of frustoconical form as shown, and has secured thereto a grooved pulley 36 which forms part of the usual friction brake commonly used in machines of this type but of no special'importance here.

The inner race of a deep groove radial bearing 31'is seated on the sleeve 30 and rests against its flange. The outer race is clamped in a seat in the bearing housing 26 by means of a cap plate 56 detachably secured to the outer face of the bearing housing. Internally the plate 56 is shaped with relation to the flanged end of the sleeve 30 to provide clearance as shown at 35. The inner race of a radial type bearing 32 is mounted on the sleeve 30 and is held in spaced relation with respect to the inner race of the bearing 31 by means of a ring 33. Interposed between the nosepiece 34 and the inner race of bearing 32 is a ring 29. When the nosepiece34 is secured to; the sleeve 30 by screws as shown it clamps the ring, the inner race of bearing 32, the ring 33 and the inner race of bearing 31, solidly against the flange at the other end of the sleeve 30. The outer race of the bearing 32 is uncomfined in the passage of the bearing housing 26.

A pin 40 on the outer face of the grooved pulley 36 is positionedto engage a hole in the head of the-spool 38 to provide a driving connection with the spool.

The pintle assembly in the bearing housing 28' includes the nosepiece or fixture 46 similar to the nosepiece 34. The other end of the sleeve: 42 is flanged and the inner race of a deep groove bearing 44 and a radial type bear ing 45, are held in spaced relation thereon by means of a ring 41. Interposed between the. inner race of the inner bearing 45 and the nosepiece 46 is a ring 43. The

bearing 44 is locked on a seat in the sleeve 48 by a threaded ring nut 54. The spacer ring 41 aids in pressing vents-the escape of the related pintle assembly from its frame member.

As shown, the sleeves 3t) and 42 are arranged so that their internal passages are axially aligned with each other and with the nosepieces and lying therein is a tiebar 58 having threaded engagement at one end with the plate 56. The tiebar is headed at the other end and bears against an anti-friction thrust bearing 60 seated in a concentric recess in the outer end of the sleeve 42. A lock washer 62 is interposed between that head and the thrust bearing 60.

As shown in Figs. 1 and 2, the bearing housing 28 is formed to provide a transverse passage in which a pair of gripping blocks 64 and 66 are slidably mounted.

These blocks are shaped on one side to engage the surface of the sleeve 48. The gripping blocks have reversely threaded passages which engage reversely threaded sections of a locking bolt 68'.

In the operation of this device a spool 38 is mounted in the cradle by removing the tiebar 58and unlocking the clamping blocks 64 and 66. The pintle assembly which includes the sleeve 48 can then be slid outwardly, Fig. 3, so that the spool 38 can be positioned between thenosepieces 34 and 46. The tiebar 58 is replaced and when .it is drawn up tight the lefthand pintle assembly, Fig. 3, slides freely towards the right. When the tie bar is drawn up the radial thrust bearing 31 will be preloaded. This comes about by the fact thatthe head of the bar 58 transmits its force through the thrust bearing 60 to the sleeve 42 which it engages. This force in turn is transmitted through the nosepiece 46 mounted on the sleeve 42, the core 38 of the spool, the nosepiece 34, and sleeve 30. The sleeve is a unit in transferring this thrust with the ring 29', the inner race of bearing 32, ring 33 and the inner race of bearing 31. Thus this whole unit tends to shift to the right, clearance making this possible, so that the deep groove bearing31 is preloaded, since its outer race is locked against any movement in the bearing housing 26 by the plate 56.

When the tie bar 58 has been properly drawn up the locking bolt 68 is drawn up tight so that the clamping blocks 64 and 66 lock the associated pintle assembly in the housing 28. The thread on the tie bar 58 is in the direction of unwinding of spool 38, viewed from the tie bar head, so as to always tend to tighten.

When the machine is in operation with cradle 16 revolving, its opposite side frame members are alternately subjected to successive maximum and minimum stresses, progressively increasing and decreasing, as is well known in the art. These stresses are divided between the side frame members 18 and 20 by reason of the fact that they are now tied together by means of the tie bar 58.

Thus the preloaded radial thrust bearing 31 is subjected in addition to its preloading force to the rapidly changing centrifugal forces incident to the operation of the machine. The bearing 31 takes maximum additional thrust in the 3 and 9 oclock positions. The thrust bearing 60 takes maximum thrust in the 9 oclock position and the deep groove bearing 44 will take some of this thrust.

With this construction it will be seen that the side frame members are not stressed at the tie bar 58 when the machine is at rest. Although the radial thrust hearing 31 is preloaded at this time, the other radial bearings are not loaded except by the weight of the parts including the loaded spool which they support. It is obvious, of course, that the thrust bearing 60 is provided because the tie bar is relatively fixed with respect to the rotation of the spool and the lefthand pintle assembly, which also revolve when the machine is in operation.

It will be apparent from the above description to those skilled in the art that many of the details of the structure herein disclosed can be varied without departure from the novel subject matter herein disclosed. The forms of the elements selected for illustration are presented solely for that purpose, and it is desired, therefore, that the scope of protection afiorded hereby be determined by the appended claims.

What is claimed is:

1. In a cable stranding machine, a rotatable spool supporting cradle having a pair of side frame members, a pintle assembly fixed in one of said side frame members including a rotatable spool supporting fixture journaled in. a thrust bearing,.a second pintle assembly axially aligned with said first pintle assembly and slidably mounted in the other side frame member and including a rotatable spool supporting fixture journaled in a hearing, a tie bar, a thrust bearing interposed between it and said second rotatable fixture, a plate secured to the frame member of the other pintle assembly, said tie bar bearing onfsaid plate, to preload said thrust bearing while clamping a spool between said fixtures, and means for locking said second pintle assembly against movement in its frame member.

2. In a cable stranding machine, a rotatable spool V supporting cradle having a pair of side frame members,

a pintle assembly fixed in one of said side frame members including a rotatable spool supporting fixture jour naled in a thrust bearing, a second pintle assembly axially aligned with said first pintle assembly and slidably mounted in the other side frame member'and including a rotatable spool supporting fixture journaled in a hearing, a tie bar, a thrust bearing interposed betweenit and said second rotatable fixture, a plate secured to the frame member of the other pintle assembly, said tie bar threadedly engaging said plate, to preload saidthrust bearing while clamping a spool between said fixtures, and means for locking said second pintle assembly against movement in its frame member.

References Cited in the file of this patent UNITED STATES PATENTS 2,048,787 Elvin et al. July 28, 1936 2,208,914 Van Hook July 23, 1940 2,681,544 Bruestle June 22, 1954 2,787,884 Bruestle Apr. 9, 1957 2,860,479 Wheater Nov. 18, 1958 

